3-d nonvolatile memory device, memory system including the 3-d nonvolatile memory device, and method of manufacturing the 3-d nonvolatile memory device

A memory system, comprising:

• a 3-D nonvolatile memory device configured to comprise a first pipe gate layer,
• a second pipe gate layer disposed over the first pipe gate layer,
• word lines stacked over the second pipe gate layer,
• memory channel layers configured to penetrate the word lines, a pipe channel layer formed in the first pipe gate layer, where the pipe channel layer is to come in contact with a bottom surface of the second pipe gate and couple lower ends of the memory channel layers,
• a memory layer configured to surround the pipe channel layer and the memory channel layers, and
• a first gate insulating layer interposed between the first pipe gate layer and the memory layer;
• and
• a memory controller configured to control the nonvolatile memory device.

A method of manufacturing a three dimensional (3-D) nonvolatile memory device, the method comprising:

• forming a first trench by etching a conductive layer for a first pipe gate layer ;
• forming a first gate insulating layer on an inside surface of the first trench;
• filling the first trench, on which the first gate insulating layer has been formed, with a sacrificial layer;
• forming a conductive layer for a second pipe gate layer on the conductive layer for the first pipe gate layer in which the sacrificial layer has been filled ;
• alternately forming first material layers and second material layers over the second pipe gate layer;
• forming second trenches coupled to the first trench by etching the first material layers, the second material layers, and the conductive layer of the second pipe gate layer;
• removing the sacrificial layer;
• forming a memory layer on inside surfaces of the first trench and of the second trenches;
• and
• forming a channel layer over the memory layer.